An organic one of these will usually contain carbon and hydrogen.
a. compound
b. molecule
c. element
d. substance

Which element in the third period would you expect to have the larger atomic radius, sodium (na) or sulfur (s)? a. sodium, because it has a higher effective nuclear charge attracting electrons in fewer energy levels. b. sodium, because it has fewer protons attracting electrons in the same energy levels. c. sulfur, because it has more protons attracting electrons in more energy levels. d. sulfur, because it has a higher effective nuclear charge attracting electrons in the same energy levels.

To save time, you can approximate the initial mass of the solid to the nearest ±1 g. for example, if you are asked to add 14.3 g of copper, add between 13 g and 15 g. which of the following sets include two samples with an equal density? which all that apply below 15.4 g gold and 18.7 g silver 15.2 g copper and 50.0 g copper 20.2 g silver and 20.2 g copper 11.2 g gold and 14.9 g gold

Problem page combustion of hydrocarbons such as pentane ( c5 h12 ) produces carbon dioxide, a "greenhouse gas." greenhouse gases in the earth's atmosphere can trap the sun's heat, raising the average temperature of the earth. for this reason there has been a great deal of international discussion about whether to regulate the production of carbon dioxide.(a) write a balanced chemical equation, including physical state symbols, for the combustion of liquid pentane into gaseous carbon dioxide and gaseous water. (b) suppose 0.350 kg of pentane are burned in air at a pressure of exactly 1 atm and a temperature of 20.0 degree c. calculate the volume of carbon dioxide gas that is produced.be sure your answer has the correct number of significant digits.